JavaScript Usage

JavaScript is very popular in web development because it allows websites to be more dynamic. It allows for the document content to be easily altered and interacted with by the user. An easy way to conceptualize it is to understand the difference between a web page and a web application. A web page is static, with the content created by HTML and the styling created by CSS. The user can navigate to other links from the page, but other than that it's not terribly interactive.

Web applications, on the other hand, require script code. Smartphone applications can change activities upon the touch of a button with an action listener class. Similarly, for a website programmed with JavaScript, clicking a button can lead to a change of HTML in the document. In short, JavaScript is used to generate and alter the HTML of a site. As different "events" happen (clicking a button, entering query), the JavaScript code responds appropriately to update the site's information.

JavaScript also makes the code more organized with the use of object-oriented programming. Separating the markup/content(HTML) from the styling (CSS) from the behavior (JavaScript) makes the code easier to write and to read. In addition to being used as a part of web browsers, it also has some other applications, such as with game development.

It does, apparently, have some limitations. For example, JavaScript itself cannot access databases. It also cannot read from or write files to the client. Despite its high degree of browser compatibility, there can also be some differences in the way it is rendered in different browsers, just like with HTML. In addition, JavaScript may be disabled in some browsers for security purposes, which keeps a good amount of websites from working the way they were meant to.